A French drain installed correctly should last 30 to 50 years. The drainage repair calls we get in Spring, TX are almost never about systems that are 30 years old — they are about systems that are 4, 5, or 6 years old and have already stopped working. The failures are repetitive. We see the same six mistakes on most callbacks, and almost every one of them was avoidable at install for a 10-to-15 percent cost difference.
This guide is for homeowners who are about to hire a drainage contractor and want to make sure they are paying for the 30-year version, not the 5-year version. If you have not yet decided whether you need a French drain at all, start with the 9 signs guide. If you have decided you need one and want installation specifics, the French drain installation guide covers process and cost.
Failure Mode 1: Missing or Undersized Geotextile Fabric
This is the dominant cause of premature French drain failure in our service area — we see it on roughly 70 percent of repair calls. Geotextile fabric is the porous mesh that wraps the trench and keeps fine clay particles from migrating into the gravel layer. Without it, or with cheap landscape fabric substituted in, fines work their way into the gravel within 3-5 years, the gravel chokes, the pipe stops draining, and the system fails entirely by year 5-8.
The correct spec is 4-ounce non-woven geotextile fabric, fully wrapping the trench (bottom, sides, and folded over the top with overlapped seams). The wrong specs we see in failed systems include: no fabric at all, lightweight 1-ounce fabric, woven landscape weed-block fabric (which clogs faster than no fabric at all), or partial wraps that leave the bottom of the trench exposed.
Question to ask a contractor: "What gauge of geotextile fabric do you use, and does it fully wrap the trench?" The right answer is "4-ounce non-woven, full wrap." Anything else is a future failure.
Failure Mode 2: Corrugated "Flex" Pipe Instead of Rigid PVC
Big-box-store drainage kits are sold with corrugated black flex pipe because it is cheap and bendable. It is also entirely wrong for a permanent French drain installation on Beaumont Clay. The corrugations trap sediment in their ridges, the pipe crushes under the weight of soil and equipment over time, and the flexibility means the pipe sags between supports, creating low spots that hold standing water and become root attractors and biofilm habitats.
The right pipe for a residential French drain in Houston-area clay is rigid 4-inch perforated PVC, specifically SDR-35 spec. It is harder to install (needs to be cut to length and joined with fittings), it costs roughly twice as much per foot as flex pipe, and it lasts 10x as long. We have pulled corrugated flex pipe out of 6-year-old failed installations crushed flat by tree roots and soil load. We have never seen rigid PVC fail that way.
Question to ask a contractor: "Do you install rigid PVC or corrugated flex pipe?" The right answer is "rigid 4-inch perforated PVC." Flex pipe in a French drain is malpractice.
Failure Mode 3: Wrong Gravel Specification
The trench is filled with gravel for a reason: water flows freely through the void spaces between large clean stones, and the gravel keeps the trench from collapsing while still letting water reach the pipe. The right gravel is washed #57 crushed stone — angular limestone or granite, roughly 3/4 inch in size, with no smaller particles or "fines" mixed in.
The wrong gravels we see in failed systems include: pea gravel (rounded, packs too tightly, slows water flow), "drainage rock" with a wide size range that includes fines (the fines clog the system from inside), or recycled crushed concrete (often contaminated with fines and degrades over time on clay). Even washed gravel can become contaminated if the contractor does not stage it on a clean surface — a single load dumped on dirt and shoveled into the trench picks up enough fines to start clogging the system.
Question to ask a contractor: "What size and grade of gravel do you use, and do you stage it on a tarp?" The right answer mentions washed #57 stone and clean staging. Anything vague is a tell.
Failure Mode 4: Insufficient or Reversed Slope
French drains work by gravity. The pipe must slope continuously from inlet to outlet at a minimum of 1% — one inch of drop per ten linear feet. Less slope and water sits in the line. Reversed slope (any section where the pipe runs uphill) creates a permanent low point where water pools, biofilm grows, and roots eventually invade.
The mistake we see most often is contractors eyeballing slope rather than measuring with a laser level. On a 60-foot run, a half-inch error in slope across the line is invisible to the naked eye but enough to create a sag that ruins the system. Every system we install gets a rotating laser level checked at multiple points before backfill. Many systems we are called out to repair have slopes that look fine until you put a laser on them.
Question to ask a contractor: "How do you verify the slope of the pipe before backfill?" The right answer is "rotating laser level, checked at multiple points." String-and-string-level or eyeballing is not acceptable on Beaumont Clay.
Failure Mode 5: Bad Discharge Point
A French drain is only as good as where the water ends up. The most common bad-discharge mistake we see is a drain that terminates in a low spot a few feet from the trench end — the water surfaces there instead of soaking in, and the homeowner ends up with a moved puddle rather than a solved problem. The second most common mistake is discharging onto a neighbor's property, which is usually illegal in Texas and creates a legal exposure for the homeowner.
The correct discharge options are: (1) a curb-cut at the street that ties into the public stormwater system, (2) a designated low area that drains off the property naturally without crossing a property line, (3) a pop-up emitter to a designed sub-grade dispersal area, or (4) a sump pit and pump where gravity discharge is not possible. If the discharge solution does not fall into one of those four categories, the drain will create new problems even if it does not technically "fail."
Question to ask a contractor: "Where will the water actually go, and how do you know it stays on my property until it reaches a legal outlet?" If they cannot draw the discharge route on a sketch, they are not designing it — they are guessing.
Failure Mode 6: No Cleanouts
Cleanouts are vertical access points along the pipe run that allow the system to be hydro-jetted clean if it ever clogs. They cost almost nothing to add at install — a cleanout fitting and a small flush-mounted cap — but they are the difference between a quick maintenance call in year 20 and a complete system rebuild. Most budget installs skip them entirely.
We install cleanouts every 50-75 feet on every project. They are flush-mounted so they disappear into the lawn and are accessible without excavation. On a 100-foot French drain, that is two cleanouts and adds a small line item to the project cost. Worth every dollar 20 years from now.
Question to ask a contractor: "How often will you install cleanouts on this run?" The right answer is "every 50 to 75 feet." Zero cleanouts is a tell that the contractor is not thinking past install day.
What a Good French Drain Specification Looks Like
Putting it all together, the spec for a French drain on Beaumont Clay that will last 30+ years:
- 4-ounce non-woven geotextile fabric, full-trench wrap with overlapped seams.
- Rigid 4-inch perforated PVC pipe (SDR-35), perforations facing down.
- Washed #57 crushed stone, no fines, staged on a clean surface.
- Minimum 1% slope, laser-verified end-to-end before backfill.
- Discharge to a curb cut, storm drain, designated low spot, or sump pit — never a neighbor's lot, never an undefined "low area."
- Cleanouts every 50-75 feet, flush-mounted to grade.
- 5-year minimum workmanship warranty in writing.
That is the specification we install on every project at Jerry Kem-Pen-Ski Landscapes. It costs modestly more than the budget version. It lasts roughly 6x longer. The math is not close.
If You Already Have a Failing French Drain
If you suspect your existing French drain has failed — symptoms returning, no flow at the discharge point, water backing up at cleanouts — we do drainage repair as well as new installs. Often the system can be partially salvaged: hydro-jetting clogged pipe, replacing failed sections with rigid PVC, re-routing a bad discharge, or adding cleanouts that were never installed. We provide free assessments on existing systems and tell you honestly whether the system is repairable or whether starting over is the right call.
Related Drainage Guides
If you are still working through the right answer for your home, these companion pieces go deeper on adjacent decisions:
- How to know if you need a French drain — the 9 signs to watch for.
- French drain installation in Spring, TX — cost, process, and material specs that matter.
- French drain vs. surface drain — which system solves which problem.
- French drain vs. sump pump in Houston clay — when a pump is mandatory and when gravity works.
Drainage projects start at $2,500 across our full service area — Spring, The Woodlands, Klein, Tomball, Cypress, and Montgomery County. Every quote is in writing after a free on-site assessment. Call (713) 447-3398 or request a free assessment.